| Title: | "Water-SDS-[BMIm]Br composite system for one-pot multicomponent synthesis of pyrano[2,3-c]pyrazole derivatives and their structural assessment by NMR, X-ray, and DFT studies" |
| Author(s): | Chakraborty S; Paul B; De UC; Natarajan R; Majumdar S; |
| Address: | "Department of Chemistry, Tripura University Suryamaninagar 799 022 India smajumdar@tripurauniv.ac.in +91-381-2374802 +91-381-237-9070. CSIR-Indian Institute of Chemical Biology 4,Raja S. C. Mullick Road Kolkata 700 032 India" |
| ISSN/ISBN: | 2046-2069 (Electronic) 2046-2069 (Linking) |
| Abstract: | "Here, we report a simple, efficient, and green protocol for the one-pot synthesis of pyrano[2,3-c]pyrazole derivatives via a sequential three-component strategy using aromatic aldehydes, malononitrile and pyrazolin-5-one in a water-SDS-ionic liquid system. This is a base and volatile organic solvent-free approach that could be applicable to a wide substrate scope. The key advantages of the method over other established protocols are very high yield, eco-friendly conditions, chromatography-free purification and recyclability of the reaction medium. Our study revealed that the N-substituent present in pyrazolinone controls the selectivity of the process. N-unsubstituted pyrazolinone favours the formation of 2,4-dihydro pyrano[2,3-c]pyrazoles whereas under identical conditions N-phenyl substituent pyrazolinone favours the formation 1,4-dihydro pyrano[2,3-c]pyrazoles. Structures of the synthesized products were established by NMR and X-ray diffraction techniques. Energy optimized structures and energy gaps between the HOMO-LUMO of some selected compounds were estimated using density functional theory to explain the extra stability of the 2,4-dihydro pyrano[2,3-c]pyrazoles over 1,4-dihydro pyrano[2,3-c]pyrazoles" |
| Notes: | "PubMed-not-MEDLINEChakraborty, Sourav Paul, Bhaswati De, Utpal Chandra Natarajan, Ramalingam Majumdar, Swapan eng England 2023/03/03 RSC Adv. 2023 Feb 27; 13(10):6747-6759. doi: 10.1039/d3ra00137g. eCollection 2023 Feb 21" |
